A treatable cause of myelopathy and vision loss mimicking neuromyelitis optica spectrum disorder: late-onset biotinidase deficiency.
Metab Brain Dis
; 32(3): 675-678, 2017 06.
Article
in En
| MEDLINE
| ID: mdl-28281033
ABSTRACT
Biotinidase deficiency is characterized by severe neurological manifestations as hypotonia, lethargy, ataxia, hearing loss, seizures and developmental retardation in its classical form. Late-onset biotinidase deficiency presents distinctly from the classical form such as limb weakness and vision problems. A 14-year-old boy presented with progressive vision loss and upper limb weakness. The patient was initiated steroid therapy with a preliminary diagnosis of neuromyelitis optica spectrum disorder due to the craniospinal imaging findings demonstrating optic nerve, brainstem and longitudinally extensive spinal cord involvement. Although the patient exhibited partial clinical improvement after pulse steroid therapy, craniocervical imaging performed one month after the initiation of steroid therapy did not show any regression. The CSF IgG index was <0.8 (normal <0.8), oligoclonal band and aquaporin-4 antibodies were negative. Metabolic investigations revealed a low biotinidase enzyme activity 8% (0.58 nmoL/min/mL; normal range 4.4 to 12). Genetic testing showed c.98-104delinsTCC and p.V457 M mutations in biotinidase (BTD) gene. At the third month of biotin replacement therapy, control craniospinal MRI demonstrated a complete regression of the lesions. The muscle strength of the case returned to normal. His visual acuity was 7/10 in the left eye and 9/10 in the right. The late-onset form of the biotinidase deficiency should be kept in mind in all patients with myelopathy with or without vision loss, particularly in those with inadequate response to steroid therapy. The family screening is important to identify asymptomatic individuals and timely treatment.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Spinal Cord Diseases
/
Vision Disorders
/
Biotin
/
Neuromyelitis Optica
/
Biotinidase Deficiency
Type of study:
Diagnostic_studies
/
Prognostic_studies
Limits:
Adolescent
/
Humans
/
Male
Language:
En
Journal:
Metab Brain Dis
Journal subject:
CEREBRO
/
METABOLISMO
Year:
2017
Document type:
Article
Affiliation country:
Turkey
Publication country:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
/
US
/
USA